Tensile strained silicon (s-Si) enhances electron mobility by lifting the conduction band degeneracies, reducing carrier scattering and increasing the population of carriers in sub-bands with lower transverse effective mass. A strain relaxed buffer (SRB) is an important element when fabricating strained channel CMOS transistors. As an example, a SiGe SRB can be used when growing on a substrate a tensile strained Si channel for nFET devices and a compressively strained Ge, or high Ge percentage Si1-xGex (e.g., where x=0.50), for pFET devices.